Dopamine-beta-hydroxylase (DBH) from bovine adrenal is purified to an apparent homogeneous form by passing through a column of DEAE cellulose, concanavalin A sepharose and sephacryl S-300 successively. On gel electrophoresis, this preparation of DBH shows only one band in the presence of 10% SDS, but two distinct bands in the absence of SDS. This result suggests that probably there is a contaminating protein with DBH having a similar molecular weight but with different charges as that of DBH. There is no significant decrease in enzyme activity of DBH after treatment with glycosidases to remove carbohydrate moiety from the enzyme molecule. The specific activity of this preparation of DBH is 22 micro moles/min/mg protein.